/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */


bool isSameTree(struct TreeNode* p, struct TreeNode* q){
    if(p == NULL && q == NULL)
        return true;
    
    if(p == NULL && q!=NULL)
        return false;

    if(p != NULL && q==NULL)
        return false;
    
    if(p->val != q->val)
        return false;

    return isSameTree(p->left,q->left)
        && isSameTree(p->right,q->right);

}